Torsion spring damper

Abstract

A torsional damper integral with a torsion bar wherein the damper is not directly connected to any support structure. Torque applied by the torsion bar to the damper on one side of the damper's mid length is equilibrated by torque exerted by the torsion bar to the damper on the opposite side of its mid length. In this manner, a part of the torsion load is transmitted to the energy dissipating damper.

What is claimed is: 
     
       1. A torsion damper system for a torsion load producing structure comprising: a torsion bar having a greater length than width which undergoes elastic deformation when subjected to a torsional load;   a means for connecting a torsional load to the torsion bar;   a layer of damping material encircling the torsion bar and bonded to said torsion bar such that a torsional load applied to the torsion bar loads the damping material in shear; and   an outer cylinder encircling the layer of damping material and bonded to said damping material to receive shear loads from said layer of damping material, said outer cylinder having no separate attachment to any other structure when the torsion damper system is connected to said torsion load producing structure.   
     
     
       2. The system as recited in claim 1 wherein said torsion bar comprises a solid metallic member. 
     
     
       3. The system as recited in claim 1 wherein said torsion bar comprises a hollow tube. 
     
     
       4. The system as recited in claim 1 wherein the thickness of said layer of damping material is substantially constant throughout the length of said cylinder. 
     
     
       5. The system as recited in claim 1 wherein the thickness of said layer of damping material varies with the distance from the longitudinal midpoint of said cylinder such that the shear load on said layer of damping material is of constant magnitude at all points along its length. 
     
     
       6. The system as recited in claim 5 wherein the thickness of said layer of damping material varies linearly with the distance from the longitudinal midpoint of said cylinder. 
     
     
       7. The system as recited in claim 1 wherein the means for connecting comprises a spline portion at one end of the torsion bar. 
     
     
       8. The system as recited in claim 1 wherein said damping material comprises a layer of rubber. 
     
     
       9. The system as recited in claim 1 wherein said damping material comprises a layer of plastic. 
     
     
       10. The system as recited in claim 1 wherein said outer cylinder is segmented into a plurality of spaced cylindrical sections coaxial with said torsion bar. 
     
     
       11. A torsion spring damper system for a torsion load producing structure comprising: a high strength, high stiffness torsion bar having a greater length than width which undergoes elastic deformation when subjected to a torsional load;   a means for connecting a torsional load to the torsion bar;   a first segmented cylindrical layer of damping material encircling the torsion bar and bonded to said torsion bar to be loaded in shear by the elastic deformation of the torsion bar;   a correspondingly segmented first outer sleeve encircling the first layer of damping material and bonded to said first segmented cylindrical layer of damping material such that the shear load of each segment of the first layer of damping material is transmitted to the corresponding segment of said segmented first outer sleeve;   a second segmented cylindrical layer of damping material encircling the first outer sleeve and bonded to said first outer sleeve to receive shear loads therefrom; and   a second outer sleeve encircling the second layer of damping material and bonded to said second segmented cylindrical layer such that the shear loads of said second segmented cylindrical layer of damping material is transmitted to said second outer sleeve, said second outer sleeve having no separate attachment to any other structure when the torsion damper system is connected to said torsion load producing structure.